I'd be wary of drawing too many conclusions from that oft-quoted statistic.
To start with, different companies use different processes to determine what exactly constitutes "R&D" expenditures.
Secondly, I think you need to recognize that Apple - unlike virtually ALL of its competitors - focuses on a relative handful of products. Compare, for example Apple's iPod, iMac, MacBook, iPhone, and iPad - at best a half dozen product families - with the literal thousands produced by, for example, Sony.
Gizmodo points out that Apple spends about $78 million per product - whereas Sony spends $11.5 million.
I think this R&D spending disparity shows up in the final products we consumers see: Unquestionably Apple products achieve a level of sophistication and delight that Sony (itself no slouch in the product department) never approaches. I also, by the way, think this gives some justification to Apple's claims RE: Trade Dress and Samsung. If Apple spends hundreds of millions gettting the "look-and-feel" of the iPhone and iPad just right - its sort of disgusting when Samsung comes along and blatantly copies that "look-and-feel."
The other thing to keep in mind is this: Apple's revenues have grown far, far faster than most of its competitors. And obviously, as that Top Line number grows, the R&D budget shrinks as a percentage. But its also important to remember that simply throwing dollars at a problem isn't necessarily any guarantee to success. Its just the fact that Apple seems to be much more efficient at how it does it - as Seeking Alpha pointed out back in 2008 - long before the iPad appeared. And long before Apple became the most valuable tech firm in the world.
Lastly, I think a key to understanding Apple, their R&D budget, and the tremendous efficiencies they've been able to achieve, is to be found in a quote from Jon Sculley's book about a visit he and Jobs had to Dr Edwin Land, inventor of the Poloroid camera:
Steve Jobs - and Apple - don't invent products. They discover them.
